The present invention relates to a process cartridge and an electrophotographic image forming apparatus to which a process cartridge is detachably mountable.
Here, the electrophotographic image forming apparatus may be an electrophotographic copying machine, an electrophotographic printer (a LED printer, a laser beam printer or the like), an electrophotographic printer type facsimile machine, an electrophotographic printer type word processor or the like.
The process cartridge may contain as a unit an electrophotographic photosensitive member and at least one of a charge member, a developing member and a cleaning member, the unit being detachably mountable to the main assembly of the electrophotographic image forming apparatus. The process cartridge make contain as a unit an electrophotographic photosensitive member and at least a developing member, the unit being detachably mountable to a main assembly of the electrophotographic image forming apparatus.
In an electrophotographic image forming apparatus using the electrophotographic image forming process, use has been made of the process cartridge type apparatus in which the process cartridge comprises as a unit the electrophotographic photosensitive member and process means actable on the electrophotographic photosensitive member, the unit being detachably mountable to the main assembly of the electrophotographic image forming apparatus. With the use of the process cartridge type apparatus, the maintenance operation can be carried out in effect by the users without the necessity of relying on serviceman, and therefore, the operability is improved. Therefore, the process cartridge type apparatus is widely used in the field of electrophotographic image forming apparatus.
Furthermore, an example of a frame of a conventional process cartridge is as follows. The frame includes a developer chamber and a developer accommodating container, the developer chamber is provided with developing means including a developing member in the form of a developing roller for supplying the developer to an electrostatic latent image formed on an electrophotographic photosensitive member, and a developer layer thickness regulating member in the form of a developing blade for regulating a thickness of a layer of the developer carried on the developing roller, and the developer accommodating container including a developer accommodating portion provided with a developer feeding member. The developing device frame is coupled with a cleaning frame to which the electrophotographic photosensitive member, the cleaning member and a charge member are mounted.
It is conventional to use a developer amount detection electrode comprising a first electroconductive portion and a second electroconductive portion which constitute a capacitor in the developing device frame as a means for detecting a remaining amount of the developer in the process cartridge. A voltage is applied between the first electroconductive portion and the second electroconductive portion, and the change of the amount of the developer is detected as a change in the electrostatic capacity between the first electroconductive portion and the second electroconductive portion. In a process cartridge having such a type of detecting system, connection electrodes for supplying a developer amount detection bias to the detection electrode from the main assembly of the electrophotographic image forming apparatus and for supplying the detection bias to the main assembly of the electrophotographic image forming apparatus, are provided.
When the process cartridge is mounted to the main assembly of the image forming apparatus, the connection electrode provided in the process cartridge is electrically connected with the connection electrode provided in the main assembly of the image forming apparatus, thereby establishing an electrical connection therebetween. By doing so, the developer amount detecting means becomes operable.
Depending on the structure of the main assembly of the image forming apparatus and/or the construction of the process cartridge, the mounting position of the connection electrode may be limited. In such a case, during the process of assembling the process cartridge or the developing frame, it is necessary to electrically connect divided connection electrodes with each other.
Accordingly, it is a principal object of the present invention to provide a process cartridge and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable in which the electrical connection in the process cartridge is assured.
It is another object of the present invention to provide a process cartridge and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable, in which the voltage received by the process cartridge from the main assembly of the apparatus can be supplied assuredly to the right member.
It is a further object of the present invention to provide a process cartridge and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable, in which the electrical connection is assured across frames.
It is a further object of the present invention to provide a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including an electrophotographic photosensitive member; a developing member for developing an electrostatic latent image formed on the electrophotographic photosensitive member; a developing device frame including a first frame portion supporting the developing member and a second frame portion having a developer accommodating portion for accommodating a developer to be used for developing the electrostatic latent image by the developing member; first and second electroconductive portions disposed to be spaced from each other to detect, by the main assembly of the apparatus, a remaining amount of the developer in the process cartridge; a cartridge contact electrically connectable with the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus, the cartridge contact being disposed in the second frame portion; a contacting electrode electrically connected with the cartridge contact, the contacting electrode being disposed in the second frame portion; a first electroconductive portion contact electrically connected with the first electroconductive portion, the first electroconductive portion contact being disposed in the first frame portion, and the first electroconductive portion contact and the contacting electrode contacting each other at a connecting portion between the first frame portion and the second frame portion.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.